Photosynthesis converts light energy into chemical energy, releasing oxygen as a by-product – and maintaining the earth’s breathable atmosphere. We associate photosynthesis mainly with plants. But imagine if your clothes could photosynthesise, absorbing carbon dioxide and emitting oxygen. Post Carbon Lab envisages a coating of living algae that could be applied to textiles to let them do just that during wear, with one square metre of fabric generating as much oxygen as a young tree. The algae would need light and an occasional misting of water to survive. Unsurprisingly, the base colour for such textiles would be green and other associated earthy hues, though the algae could be manipulated to change colour to warn of neglect. More conventionally, Post Carbon Lab is also working on bacterial pigment dyeing processes.